Conventional multichannel analyzers (MCA) operate with the analog-to--digital conversion process linked to a clock or gate pulse. The actual conversion of an analog signal to a digital readout occurs only when synchronized to a gate pulse, thereby resulting in a "stair-step" response. If the analog signal is smaller than a given size, it is inserted into a lower channel; if the analog signal is larger than a given size, it is inserted into a higher bin. When observing energy spectra, the user must spread the signal out over many channels to find the centroid or average energy. In one particular environment, this has resulted in the adoption of 8196 channel multichannel analyzers to record the gamma energy spectrum from germanium detectors. The individual gamma ray lines are typically spread out over several channels to allow the user to determine the centroid or exact energy of the gamma ray. This necessitates very large data files and "power-hungry" electronics to be able to perform the analog-to-digital conversion in a short time.
"Total dose meters" determine the absorbed dose or dose equivalent in mixed radiation fields. It was believed that multichannel analyzers would be useful in such devices. However, total dose meters operate in an environment wherein the pulse height spectrum covers four orders of magnitude, or more. Conventional analog-to-digital converters (ADCs) require too much power to be useful in this range.